Description: The positive Pell solutions are precisely the integer powers of the fundamental solution. To get the general solution set (which we will not be using), throw in a copy of Z/2Z. (Contributed by Stefan O'Rear, 19-Sep-2014)
Ref | Expression | ||
---|---|---|---|
Assertion | pellfund14b | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | pellfund14 | |
|
2 | simpll | |
|
3 | pell1qrss14 | |
|
4 | pellfundex | |
|
5 | 3 4 | sseldd | |
6 | 5 | ad2antrr | |
7 | simplr | |
|
8 | pell14qrexpcl | |
|
9 | 2 6 7 8 | syl3anc | |
10 | eleq1 | |
|
11 | 10 | adantl | |
12 | 9 11 | mpbird | |
13 | 12 | r19.29an | |
14 | 1 13 | impbida | |